Chalice is a new Python serverless microframework for AWS. In this session, we'll show how to use it to create serverless REST APIs that use Amazon API Gateway and AWS Lambda. We'll deploy our first REST API in less than 30 seconds. Several live demos will show how to build on this example to leverage other Chalice capabilities, including advanced URL routing, automatic policy generation, and Swagger exports.

1. © 2016, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
James Saryerwinnie / AWS
December 2, 2016
DEV308
Chalice
A Serverless Microframework for Python

2. Agenda
Serverless REST APIs
Getting started with chalice
Chalice sample applications with demos

3. Assumptions
{…} REST API

4. REST APIs

5. REST API
Client
Mobile client
REST APIs

6. REST API
REST APIs
GET /users HTTP/1.1
{"users": […]}

7. REST API
REST APIs
Amazon
DynamoDB
Memcached
Amazon
CloudWatch

8. Auto Scaling group
Security group
Elastic Load
Balancing
Instance
REST API
REST APIs
Amazon
DynamoDB
Memcached
Amazon
CloudWatch

9. Serverless REST APIs

10. Auto Scaling group
Security group
Instance
Elastic Load
Balancing
REST API

11. REST API
Amazon API Gateway
AWS Lambda

12. Amazon API Gateway
Create, maintain, and secure APIs at any scale
Handles authorization, access control, and monitoring
Acts as a “front door” for applications

13. AWS Lambda
Run code without thinking about servers
Pay for only the compute time you consume
Lambda takes care of everything required to run and
scale your code with high availability

14. First serverless API

15. REST API
First serverless API
GET / HTTP/1.1
{"hello": "world"}

16. Demo

17. REST API
First serverless API
GET / HTTP/1.1
{"hello": "world"}

18. AWS Management Console

19. What about?

20. Amazon API Gateway AWS Lambda

21. SDK
Lambda.GetFunction(params: {'body': '', 'url': u'h
IAM.GetRole(params: {'body': {'Action': u'GetRole'
IAM.CreateRole(params: {'body': {'Action': u'Creat
IAM.PutRolePolicy(params: {'body': {'Action': u'Pu
Lambda.CreateFunction(params: (... omitted from lo
APIGateway.GetRestApis(params: {'body': '', 'url':
APIGateway.CreateRestApi(params: {'body': '{"name"
APIGateway.GetResources(params: {'body': '', 'url'
APIGateway.PutMethod(params: {'body': '{"authoriza

22. Introducing chalice

23. from chalice import Chalice
app = Chalice(app_name='helloworld')
@app.route('/')
def index():
return {'hello': 'world'}
app.pyHello World app

24. from chalice import Chalice
app = Chalice(app_name='helloworld')
@app.route('/')
def index():
return {'hello': 'world'}
app.pyHello World app
1. App object

25. from chalice import Chalice
app = Chalice(app_name='helloworld')
@app.route('/')
def index():
return {'hello': 'world'}
app.pyHello World app
1.
2.
App object
Routes

26. from chalice import Chalice
app = Chalice(app_name='helloworld')
@app.route('/')
def index():
return {'hello': 'world'}
app.pyHello World app
1.
2.
App object
Routes
3. File

27. from chalice import Chalice
app = Chalice(app_name='helloworld')
@app.route('/')
def index():
return {'hello': 'world'}
app.pyHello World app
$ chalice deploy
https://dfut7pnl47/dev/

28. Demo

29. Chalice API

30. from chalice import BadRequestError
@app.route('/cities/{city}')
def state_of_city(city):
try:
return {'state': CITIES_TO_STATE[city]}
except KeyError:
raise BadRequestError(
"Unknown city '%s', valid choices are: %s" %
( city, ', '.join(CITIES_TO_STATE.keys())))
app.pyError handling

31. from chalice import BadRequestError
@app.route('/cities/{city}')
def state_of_city(city):
try:
return {'state': CITIES_TO_STATE[city]}
except KeyError:
raise BadRequestError(
"Unknown city '%s', valid choices are: %s" %
( city, ', '.join(CITIES_TO_STATE.keys())))
app.pyError handling

32. from chalice import BadRequestError
@app.route('/cities/{city}')
def state_of_city(city):
try:
return {'state': CITIES_TO_STATE[city]}
except KeyError:
raise BadRequestError(
"Unknown city '%s', valid choices are: %s" %
( city, ', '.join(CITIES_TO_STATE.keys())))
app.pyError handling

33. from chalice import BadRequestError
@app.route('/cities/{city}')
def state_of_city(city):
try:
return {'state': CITIES_TO_STATE[city]}
except KeyError:
raise BadRequestError(
"Unknown city '%s', valid choices are: %s" %
( city, ', '.join(CITIES_TO_STATE.keys())))
app.pyError handling
HTTP/1.1 400 Bad Request
{
"Code": "BadRequestError",
"Message": "BadRequestError: Unknown city 'vancouver', valid choices are: portland, seattle"
}

34. from chalice import NotFoundError
OBJECTS = {
}
@app.route('/objects/{key}', methods=['GET', 'PUT'])
def myobject(key):
request = app.current_request
if request.method == 'PUT':
OBJECTS[key] = request.json_body
elif request.method == 'GET':
try:
return {key: OBJECTS[key]}
except KeyError:
raise NotFoundError(key)
app.pyRequest metadata

35. from chalice import NotFoundError
OBJECTS = {
}
@app.route('/objects/{key}', methods=['GET', 'PUT'])
def myobject(key):
request = app.current_request
if request.method == 'PUT':
OBJECTS[key] = request.json_body
elif request.method == 'GET':
try:
return {key: OBJECTS[key]}
except KeyError:
raise NotFoundError(key)
app.pyRequest metadata

36. from chalice import NotFoundError
OBJECTS = {
}
@app.route('/objects/{key}', methods=['GET', 'PUT'])
def myobject(key):
request = app.current_request
if request.method == 'PUT':
OBJECTS[key] = request.json_body
elif request.method == 'GET':
try:
return {key: OBJECTS[key]}
except KeyError:
raise NotFoundError(key)
app.pyRequest metadata
Updated every request

37. from chalice import NotFoundError
OBJECTS = {
}
@app.route('/objects/{key}', methods=['GET', 'PUT'])
def myobject(key):
request = app.current_request
if request.method == 'PUT':
OBJECTS[key] = request.json_body
elif request.method == 'GET':
try:
return {key: OBJECTS[key]}
except KeyError:
raise NotFoundError(key)
app.pyRequest metadata

38. app.pyPet store
@app.route('/')
def index():
return {}
@app.route('/login', methods=['POST'])
def login():
return {}
@app.route('/pets', methods=['POST', 'GET'])
def pets():
return {}
@app.route('/pets/{pet_id}', methods=['GET'])
def pet(pet_id):
return {}
@app.route('/users', methods=['POST'])
def users():
return {}

39. @app.route('/')
def index():
return {}
@app.route('/login', methods=['POST'])
def login():
return {}
@app.route('/pets', methods=['POST', 'GET'])
def pets():
return {}
@app.route('/pets/{pet_id}', methods=['GET'])
def pet(pet_id):
return {}
@app.route('/users', methods=['POST'])
def users():
return {}
app.pyPet store

40. Chalice architecture
Lambda runtime and APIs
Command line interface
Configuration, packaging, and deployment

41. Client
Lambda runtime and API
Amazon API Gateway AWS Lambda
GET /users HTTP/1.1 API call
{"hello": "world"}HTTP/1.1 200 OK
Date: …
{"hello": "world"}

42. Client
Lambda runtime and API
Amazon API Gateway AWS Lambda
Chalice

43. Client
Lambda runtime and API
Amazon API Gateway AWS Lambda
Chalice

44. Lambda runtime and API
AWS Lambda

45. Lambda runtime and API
Lambda
handler.py
def lambda_handler(event, context):
# Called by lambda runtime.
return 'Hello from Lambda'AWS Lambda

46. Lambda runtime and API
Lambda
chalice
from chalice import Chalice
app = Chalice(app_name='helloworld')
@app.route('/')
def index():
return {'hello': 'world'}
app.py
AWS Lambda

47. Chalice architecture
Lambda runtime and APIs
Command line interface
Configuration, packaging, and deployment

48. Chalice architecture
CLI
.
├── app.py
└── requirements.txt

49. Chalice architecture
CLI
.
├── app.py
└── requirements.txt
$ chalice deploy

50. Chalice architecture
CLI
.
├── app.py
└── requirements.txt
deploy.zip

51. Chalice architecture
CLI
.
├── app.py
└── requirements.txt
deploy.zipdeploy.zip
Chalice runtime

52. Chalice architecture
CLI
.
├── app.py
└── requirements.txt
deploy.zipdeploy.zip
Chalice runtime

53. Chalice architecture
CLI
.
├── app.py
└── requirements.txt
deploy.zip

54. Chalice architecture
CLI
.
├── app.py
└── requirements.txt Amazon API Gateway AWS Lambda

55. What we learned
Setting up chalice
Create a new chalice project
Deploying our app
Chalice routing API

56. Github bot
Sample application

57. Github bot flow

58. Github bot flow

59. Github bot flow

60. Github bot flow

61. Github bot flow

62. Github bot flow

63. Github bot flow

64. Github bot flow

65. Demo

66. What we learned
Managing secrets and config
Multifile chalice applications
Configuring debug logs
Viewing Amazon CloudWatch Logs

67. Single page app

68. What we learned
Local mode
Javascript SDK generation
Integrating with Amazon Cognito

69. Wrapping up
Serverless REST APIs
Chalice API
Github bot
Single page app
User pool integration

70. Remember to complete
your evaluations!

71. Thank you!
• https://github.com/awslabs/chalice
• http://chalice.readthedocs.io/